Wire fabric

ABSTRACT

A wire fabric consisting of sets of longitudinal strands and cross strands, at least one of said sets including spring steel wires, the cross strands piercing said longitudinal strands to prevent slippage thereof lengthwise of said longitudinal strands, the cross strands being gripped frictionally in the longitudinal strands, or offset laterally at each of the longitudinal strands, or both, to prevent lengthwise slippage of the cross strands relative to the longitudinal strands.

United States Patent 1191 Platt et al.

[ 1 Aug. 13, 1974 WIRE FABRlC [75] Inventors: Thomas W. Platt; Harmon W.

Arnold, both of Carthage, Mo.

[73] Assignee: Flex-O-Lators, lnc., Carthage, Mo.

[56] References Cited UNITED STATES PATENTS 1,045,856 12/1912 Klipfel et al. 245/11 2,267,881 12/1941 Williams et a1. 5/186 R 2,341,254 2/1944 Williams et a1.... 5/354 2,803,293 8/1957 Rowland 5/309 3,195,955 7/1965 Richardson et al.... ..'5/l9l 3,327,332 6/1967 Richardson et al.... 297/456 3,733,625 5/1973 Platt et a1. 5/191 Primary Examiner-Richard .1. Herbst Attorney, Agent, or Firm.l0hn A. Hamilton [57] ABSTRACT A wire fabric consisting of sets of longitudinal strands and cross strands, at least one of said sets including spring steel wires, the cross strands piercing said longitudinal strands to prevent slippage thereof lengthwise of said longitudinal strands, the cross strands being gripped frictionally in the longitudinal strands, or offset laterally at each of the longitudinal strands, or both, to prevent lengthwise slippage of the cross strands relative to the longitudinal strands.

10 Claims, 19 Drawing Figures PATENIEB mm 31m SNEU 1 BF 2 PATENTED Aum 31914 SHEEI 2 BF 2 WIRE FABRIC This invention relates to new and useful improvements in wire fabric, and has particular reference to a wire fabric especially adapted for use in upholstered seating for automotive and furniture applications, although the fabric shown obviously may be used for general purposes. In upholstered seating, wire fabric is commonly used either as a spring base for padding material, especially when it is resiliently supported in a seating frame along one or more of its edges, or as a padding insulator", in which usage it is laid between padding layers and the spring base of the seat, in order to prevent the padding material from working down between the spring wires forming the spring base during the life of the seat.

The economical production of wire fabric of this type has been a difficult problem, especially where the fabric includes resilient spring steel wires, in that it is difficult to secure intersecting spring steel wires together in such a manner as to prevent relative movement or slippage thereof, so that the fabric maintains its form and shape in long periods of usage. Intersecting wires can of course be welded or soldered together, but any such process involving a high degree of heat causes the wires to lose at least some of their spring temper at these points, so that they become brittle and tend to break when repeatedly flexed, so that the useful life of the fabric is shortened. Also, any sharp bending or crimping of spring steel wires, to form an interlocking connection between intersecting wires, produces a workhardening of the wires, also resulting in loss of spring temper and shortening of the useful life of the .fabric. Also, welding, as well as certain types of mechanical interlocks, of intersecting wires produces or tends to produce'a rigid connection of the wires, so that they cannot pivot relatively to each other in the plane of the fabric. In the discussed upholstery usages of the fabric, it is often deflected quite irregularly, being bowed and warped transversely of its plane to a marked degree,

and such movement does tend to pivot the intersecting wires in the plane of the fabric. Any fixed rigidity of the connection hence imposes severe stresses on the wires at the connection.

Accordingly, the object of the present invention is wire at its point of intersection with each longitudinal strand, or both.

Other objects are simplicity and economy of construction, efficiency and dependability of operation, and ready adaptability for production by automatic equipment.

With these objects in view, as well as other objects which will appear in the course of the specification, reference will be had to the accompanying drawing, wherein:

FIG. 1 is a top plan view of a wire fabric embodying the present invention,

FIG. 2 is a sectional view taken on line IIII of FIG.

FIG. 3 is a fragmentary, enlarged sectional view taken on line III--III of FIG. 1,

FIG. 4 is a view similar to FIG. 3, showing a modification of structure,

FIG. 5 is a fragmentary view similar to FIG. 1, showing another modification of structure,

FIG. 6 is an enlarged, fragmentary sectional view taken on line VI-VIof FIG. 5,

FIG. 7 is a fragmentary sectional view taken on line VIl-VII of FIG. 6,

FIG. 8 is a view similar to FIG. 7, showing a modification of structure,

FIG. 9 is a fragmentary view similar to FIG. 1, showing another modification of structure,

FIG. 10 is an-enlarged, fragmentary sectional view taken on line X-X of FIG. 9,

FIG. 11 is a sectional view taken on line XI-XI of FIG. 10,

the provision of a wire fabric which largely solves all of v the above enumerated problems, in that at the strand intersections, each strand is securely fastened against movement longitudinally of itself and transversely to the other strand, that the connection of intersecting strands involves no welding, soldering or sharp bending of the strands, and that the connection of intersecting strands permits a degree of pivotal movement between said strands in the plane of the fabric.

Generally, these objects are accomplished by the provision of a fabric in which one set of the strands, say t the longitudinal strands, which usually but not always I include a spring steel wire, are provided with a portion 0 of relatively soft, non-metallic material, the spring steel cross wires piercing said non-metallic portions of the longitudinal strands. This prevents lengthwise movement of the longitudinal strands relative to the cross wires. Longitudinal movement of the cross wires relative to the longitudinal strands is prevented either by the frictional grip of the non-metallic portions of the strands thereon, or by forming an offset in each cross FIG. 12 is a view similar to FIG. 11, showing a modification of structure, I

FIG. 13 is a fragmentary view similar to FIG. 1, showing another modification .of structure,

FIG. 14 is an enlarged, fragmentary sectional view taken on line XIVXIV of FIG. 13,

FIG. 15 is a view similar to FIG. 14, showing a mo dification of structure,

FIG. 16 is a fragmentary view similar to FIG. 1, showing another modification of structure,

FIG. 17 is an enlarged, fragmentary sectional view taken on line XVII-XVII of FIG. 16,

FIG. 18 is a fragmentary view similar to FIG. 1 showing another modification of structure, and

FIG. 19 is an enlarged, fragmentary sectional view taken on line XIX XIX of FIG. 18.

Like reference numerals apply to similar parts throughout the several views, and the numeral 2 applies generally to a fragmentary portion of a wire fabric embodying the present invention. Said fabric includes parallel, spaced apart longitudinal strands each indicated generally by the numeral 4, and cross strands comprising spring steel wires each indicated by the numeral 6 which are parallel to each other and disposed generally at right angles to longitudinal strands 4.

In the upholstery usages of the fabric discussed above, it is loaded principally from one side thereof, and it will be understood that in the drawing, the load surface thereof is the top surface thereof, as shown. Cross wires 6 should be close enough together to adequately support padding material applied over the fabric, a spacing of about one inch having been found to be adequately small for most types of padding materials while longitudinal strands 4, which serve to integrate the fabric and maintain the spacing of the cross wires along their lengths, may be more widely spaced apart. Longitudinal strands 4 may or may not include spring steel wires, depending on whether it is desired that the fabric be resilient only about lines thereof at right angles to said cross wires, in which the longitudinal strands may be of pliable material, or whether it is desired that the fabric also be resilient about lines parallel to the cross wires, in which case the longitudinal strands also include spring wires.

' In the species of the invention shown in FIGS. 1-3, each longitudinal strand 4 includes a spring steel wire 8 having a sheath 10 having a flap 12 extending radially therefrom. Said sheath and flap are preferably formed of a plastic of the type commonly known as plastic with a memory, which is elastic and tends strongly to recover its original form when it is deformed. Plastics of the polyolefin class, such as polyethylene and polypropylene, are quite satisfactory. They may be economically applied to wire 8 by an extrusion process. Cross wires 6 pierce flap 12 at spaced points therealong, and are laterally offset from wires 8. This piercing by wires 6 may be accomplished in automatic machinery by feeding, or shooting wires 6, longitudinally of themselves, successively through suitable guides properly related to longitudinal strands 4, which are held in suitable dies or clamps. In use, cross wires 6 are of course secured against movement along strands 4 by their engagement in flap 12 of said strand, while wires 6 are prevented from slipping longitudinally of themselves through said flap by frictional resistance to any sliding movement thereof through the flap. This friction is introduced by the strong tendency of the plastic to recover and grip wires 6 tightly, after it has been pierced by said wires. At the same time, the plastic flap is also sufficiently flexible to permit a degree of relative pivoting of wires 6 relative to wires 8 in the plane of the fabric. In some severe usages, the frictional grip of the plastic flaps on wires 6 may not be sufficient to prevent wires 6 from sliding longitudinally of themselves through the flaps, and in such cases the security of the connection may be increased by the modification shown in FIG. 4 in which each cross wire 6 is transversely offset or crimped, as shown at 14, at each longitudinal strand 4. Oridinarily, the crimps would be formed after the cross wires have been shot" into piercing relationship to flaps 12. Preferably, the crimps are offset downwardly with sheaths 10 of the longitudinal strands resting therein as shown. This arrangement permits the standing portions of wires 6 to be elevated to the level of the top edges of strands 4, so that the fabric presents a smoother, more nearly planar load surface, and also provides that the padding material applied over the fabric will tend to keep strands 4 firmly engaged in the crimps. In any event the curvatures of wires 6 involved in the crimps should be as gentle and gradual as possible to avoid work-hardening and loss of temper, and the tendency of the padding to hold therebeneath, and each extends through a loop defined by each strap and a narrow band 18 of said strap along the midline thereof which is struck downwardly from the standing portion thereof. Straps 16 may be of spring steel if resilience of the fabric along lines at right angles thereto is desired, or of a cheaper low carbon steel if not. The wires 6 are preferably shot longitudinally into place as before. If bands 18 are struck downwardly somewhat less than the diameters of wires 6, so that the loops formed thereby must be expanded somewhat to admit wires 6, even low carbon steel will possess sufficient elastic recovery to cause the loops to grip wires 6 firmly therein, whereby to resist longitudinal slippage of said wires. Also, if bands 18 are sufficiently narrow,

they will permit a degree of relative pivotal movement between the straps and wires in the plane of the fabric. A band width of about l/l6 of an inch has been found satisfactory in this respect although even wider bands may be used. If the frictional grip on wires 6 provided by bands 18 is not sufficient to prevent longitudinal slippage of said wires, as might occur in severe usages, each wire 6, or periodic wires, may be crimped at each side of each strap 16, as shown at 20 in FIG. 8, whereby to form an offset 22 in which the strap rests.

In the species of the invention shown in FIGS. 9-12, each longitudinal strand 4 includes a pair of parallel spring wires 24 disposed respectively above and below cross wires 6, and enclosed, by an extrusion process or otherwise, in a sheath 26 of plastic or the like, preferably of the type described in connection with FIGS. 1-4. Said sheath includes two cylindrical portions 28 in which wires 24 are respectively and axially enclosed, connected by a relatively thinner web 30, which is pierced by cross wires 6. The function of this species is generally identical to that of the species shown in F IGS. 1-4, and wires 6, or periodic wires, may also be crimped at each longitudinal strand, as shown at 32 in FIG. 12. However, the use of the two spaced apart wires in each longitudinal strand constitutes said strand as a form of trussed beam, one wire tending to be subjected to compressive stress while the other is subjected to tensile stress, when the fabric is flexed. This type of reinforced longitudinal strand may therefore be used when it is desired that the fabric have agreater resilient strength about lines at right angles to said strands, or where it may be desired to use fewer, more widely space apart longitudinal strands.

As has been mentioned above, some usages of the fabric may not require that it possess any significant degree of resilient stiffness about lines thereof at right angles to its longitudinal strands, and in such cases longitudinal strands not including spring steel wires or other metallic elements may be used. FIGS. 13-15 accordingly show a species of the invention in which each longitudinal strand 4 consists of a tube 34 as shown, or solid strand of a flexible plastic, preferably of the type described in connection with FIGS. 1-4, pierced by cross wires 6. The plastic provides a frictional grip on wires 6, as before, although here again wires 6, or certain of them, may be crimped at each longitudinal strand, as shown at 36 in FIG. 15, for severe usages. The plastic strand in most cases would be too thick to permit direct pivotal movement of the wires 6 relative thereto in the plane of the fabric, but nonetheless said wires may still pivot relative to the general lines of the plastic strands, in the plane of the fabric, as a result of the flexible yieldability of said strands, intermediate the successive cross wires.

FIGS. 16 and 17 show another species of the invention using no spring wires in its longitudinal strands. In this species, each longitudinal strand 4 consists of a cord 38 of a soft, flexible material such as twisted paper, and is pierced by each cross wire 6. Paper cords are sufficiently soft to permit pivotal movement of wires 6 relative thereto in the plane of the fabric, but also do not provide a frictional grip on the wires to prevent longitudinal slippage of said wires. Hence, the crimping of each wire 6, or certain of said wires, at each longitudinal strand, as shown at 40, is necessary rather than optional as in the species heretofore described.

FIGS. 18 and 19 show a species of the invention somewhat similar to that shown in FIG. 4, each longitudinal strand 4 including a spring wire 42, except that the sheath 44 of said wire is formed of twisted paper of the like as in FIGS. 16-17, and is of generally oval cross-sectional contour with wire 42 disposed adjacent one edge of said contour, whereby the opposite edge of said sheat forms a flap 46 which is pierced by cross wires 6. Here again, as in FIGS. 16-17 and for the same reason, the crimping of wires 6, or certain of them, at each longitudinal strand, as shown at 48, is necessary rather than optional.

While we have shown and described a number of specific embodiments of our invention, it will be readily apparent that many other minor changes of structure and operation can be made without departing from the spirit of the invention. For example, the longitudinal strands 4 might be formed of other materials, such as plastic-coated paper cords, and the crimping of the cross wires 6, as shown in FIGS. 4, 8, 12, 15, 17 and 19, could be performed in planes other than a plane normal to the fabric, such as directly in the plane of the fabric. The crimps would still perform their functions substantially as described. In the case of FIG. 8, the crimps 20 would then probably be disposed adjacent band 18, rather than at the extreme edges of strip 16.

We claim:

1. A wire fabric comprising:

a. a series of generally parallel longitudinal strands,

each of said longitudinal strands including a longitudinal element formed of elastic non-metallic material having transverse openings formed laterally therethrough at intervals along its length, and

b. a series of generally parallel cross strands, each constituting a spring steel wire extending generally at right angles to each longitudinal strands in inter secting relation thereto and projecting through a corresponding opening of said longitudinal strand, said openings normally being of smaller diameter than said cross strands, whereby said openings are resiliently enlarged by the projection of said cross wires therethrough, whereby said cross wires are gripped frictionally by said longitudinal strands to resist lengthwise slippage thereof relative to said longitudinal strands.

2. A wire fabric as recited in claim 1 wherein each longitudinal strand includes a longitudinally extending element of a relatively soft, non-metallic, elastic material capable of being pierced by said cross wires, each of said cross wires piercing said non-metallic element of each of said longitudinal strands, the elasticity of said element providing a frictional engagement thereof with said cross wire.

3. A wire fabric as recited in claim 2 wherein said non-metallic element of each longitudinal strand is formed of elastically flexible plastic of the polyolefin class including polyethylene and polypropylene.

4. A wire fabric as recited in claim 2 wherein each of said longitudinal strands includes a spring steel wire, and wherein the non-metallic element thereof extends radially of said wire transversely to a plane defined by the wires of said longitudinal strands, each of said cross wires piercing said non-metallic element in transversely offset relation from the spring wire of said longitudinal strand.

5. A wire fabric as recited in claim 1 wherein each of said cross strands comprises a spring steel wire, at least certain of said cross wires being transversely offset at each longitudinal strand to form a crimp in which said longitudinal strand is engaged.

6. -A wire fabric as recited in claim 1 wherein each of said longitudinal strands includes a spring wire core having an enclosing sheath formed of a relatively soft, elastic non-metallic material, said sheath having an integral longitudinal flap extending radially therefrom, and wherein said cross strands comprise spring steel wires piercing said flap at intervals therealong.

7. A wire fabric as recited in claim 6 wherein at least certain of said cross wires are laterally offset at each of said longitudinal strands to form a crimp within which said longitudinal strand is engaged.

8. A wire fabric as recited in claim 1 wherein each of said longitudinal strands constitutes a pair of generally parallel spring steel wires disposed respectively at opposite sides of a plane established by said cross strands, and a sheath of a relatively soft, non-metallic material enclosing said spring wires, and wherein said cross strands each consists of a spring steel wire which pierces the sheaths of said longitudinal strands intermediate the spring wires of the latter.

9. A wire fabric as recited in claim 8 wherein said sheath is formed of a flexibly elastic plastic material.

longitudinal strands are engaged. 

1. A wire fabric comprising: a. a series of generally parallel longitudinal strands, each of said longitudinal strands including a longitudinal element formed of elastic non-metallic material having transverse openings formed laterally therethrough at intervals along its length, and b. a series of generally parallel cross strands, each constituting a spring steel wire extending generally at right angles to each longitudinal strands in intersecting relation thereto and projecting through a corresponding opening of said longitudinal strand, said openings normally being of smaller diameter than said cross strands, whereby said openings are resiliently enlarged by the projection of said cross wires therethrough, whereby said cross wires are gripped frictionally by said longitudinal strands to resist lengthwise slippage thereof relative to said longitudinal strands.
 2. A wire fabric as recited in claim 1 wherein each longitudinal strand includes a longitudinally extending element of a relatively soft, non-metallic, elastic material capable of being pierced by said cross wires, each of said cross wires piercing said non-metallic element of each of said longitudinal strands, the elasticity of said element providing a frictional engagement thereof with said cross wire.
 3. A wire fabric as recited in claim 2 wherein said non-metallic element of each longitudinal strand is formed of elastically flexible plastic of the polyolefin class including polyethylene and polypropylene.
 4. A wire fabric as recited in claim 2 wherein each of said longitudinal strands includes a spring steel wire, and wherein the non-metallic element thereof extends radially of said wire transversely to a plane defined by the wires of said longitudinal strands, each of said cross wires piercing said non-metallic element in transversely offset relation from the spring wire of said longitudinal strand.
 5. A wire fabric as recited in claim 1 wherein each of said cross strands comprises a spring steel wire, at least certain of said cross wires being transversely offset at each longitudinal strand to form a crimp in which said longitudinal strand is engaged.
 6. A wire fabric as recited in claim 1 wherein each of said longitudinal strands includes a spring wire core having an enclosing sheath formed of a relatively soft, elastic non-metallic material, said sheath having an integral longitudinal flap extending radially therefrom, and wherein said cross strands comprise spring steel wires piercing said flap at intervals therealong.
 7. A wire fabric as recited in claim 6 wherein at least certain of said cross wires are laterally offset at each of said longitudinal strands to form a crimp within which said longitudinal strand is engaged.
 8. A Wire fabric as recited in claim 1 wherein each of said longitudinal strands constitutes a pair of generally parallel spring steel wires disposed respectively at opposite sides of a plane established by said cross strands, and a sheath of a relatively soft, non-metallic material enclosing said spring wires, and wherein said cross strands each consists of a spring steel wire which pierces the sheaths of said longitudinal strands intermediate the spring wires of the latter.
 9. A wire fabric as recited in claim 8 wherein said sheath is formed of a flexibly elastic plastic material.
 10. A wire fabric as recited in claim 8 wherein at least certain of said cross wires are laterally offset at each of said longitudinal strands to form crimps in which said longitudinal strands are engaged. 